Safety appliance for electric railways.



1. c. THOMPSON. SAFETY APPLIANCE FOR ELECTRIC RAILWAYS.

APPLICATION FlLED FEB- 25, I915- Patented June 20, 1916.

'ruF. COLUMIHA PLANOGRAIH co., WASHINGTON, n. c.

JAMES C. THOMPSON, 0F LEMOYNE, PENNSYLVANIA.

SAFETY APPLIANCE FOR ELECTRIC RAILWAYS.

Specification of Letters Patent.

Patented June 20 1916..

Application filed February 25, 1915. Serial No. 10,555.

To all whom it may concern:

Be it known that 1, JAMES C. THOMPSON,

cated a derailing switch, or other means positively arresting the progress of the car until shifted under conditions which insure safety, or a section of track to be guarded by visual or other appliances which forbid passing until shifted under circumstances which insure safe passage.

The invention finds its most advantageous application in connection with a' railway over which the rolling stock is propelled by electricity, first because utilizing electric current for actuating the motors which move the safety appliances from danger position to safety position, and vice versa, and secondly because employing electric current controlled by the presence of rolling stock, for determining 'the application of current to the safety appliance motors.

One object of the invention is to provide a simplified but safe and reliable, operating unit to be used in a system of the general nature above outlined, and embodying in its organization, a setting motor which will be actuated to establish the danger condition whenever a car approaches, and can have its current applied to establish the safety condition only by manual operation performed at such a point or under such conditions, as will insure a knowledge on the part of the operator, whether or not safety conditions actually exist; and to these ends, one feature of the invention consists in having an electrically controlled actuating motor responsive to two circuits, which I call the danger circuit and'the safety circuit, adapted, respectively, to establish through the medium of the motor, the danger condition and the safety condition, each of which circuits is supplied with current directly or indirectly from the working or other conductor of the railway line, and which circuits are provided with make-and-break devices reciprocally acting in the sense that they are so arranged that When the danger circuit is closed, the safety circuit is open, and vice versa, and preferably in the form of a don ble-act1ng relay; the danger circuit also including an additional interrupter preferably in the form of a normally open relay under control of a pilot circuit, which is in turn controlled by the approach of a car, so as to lnsure the danger position of the appliance whenever the car approaches; the doubleacting relay being preferably biased to normally close its break in the danger circuit, and being actuated to close its saftey circuit break, by a manually actuated circuit, which includes a switch at a remote point of control, such as a point of observation or other station inaccessible without leaving the car.

Another object is to adapt a unit equipment, such as above outlined, for application to each end of a track section where similar conditions obtain, and to render both units operative, so far as its danger position is concerned, by the approach of a car to either end, for which purpose another feature of the invention consists in having a common pilot circuit for both ends of the system, which is connected alike to the sec ond break relay in each danger circuit; each unit, however, having its own independent and manually actuated circuit and controlling switch, so that while both appliances are thrown to danger position by a car approaching either end, only that one will be restored to safety and permit the car to enter, which lies at the end of approach.

A further object is to provide means which will insure reliable operation and permit economical installation of the system and, therefore, further features of the invention consist in the particular arrangement of parts, but these can best be explained by the following detailed description of the preferred embodiment which has been selected to illustrate the general principles of the invention above outlined.

In the accompanying drawings Figure l is a schematic view of a railway crossing, one of the intersecting lines of which is a so-called electric railway and has one embodiment of my invention applied thereto, by way of illustration. Fig. 2 is a detail view of a suggested form of actuating motor, which, however, forms no part of the present invention. Fig. 3 is a detail view of the car-actuated switch which I prefer to use for controlling the pilot circuits, the

. stance the track of a steamoperated raildetails of .which, however, are reserved to be claimed in a separate application. Fig. 4 is a detail view of a form of switch that may be employed for controlling the manually actuated circuit.

A represents one right-of-way, for inway, and B an intersecting right-of-way, for instance the track of an electric railway.

C and C represent known types of derailing switches located at the respective ends of the section of the electric railway track, which is affected by the steam railway crossing, and D, D represent any suitable known type of switch-actuating motors for positively moving the switch points to either their open positions, which I shall hereinafter call danger position, or to their closed positions, which I shall hereinafter refer to as safety position.

The switches C and C are not to be taken as limitations in the invention, but merely as types of any one of a number of safety appliances adapted to assume either of two alternative conditions, such for instance as .a track switch, a visual or audible signal, a

switch for controlling the delivery of our- 7 rent to the working conductor of the electric railway, or even a crossing gate. Hence this element will hereinafter be referred to as the. safety appliance, except when it is desired to specifically indicate a switch, for

which the illustrative embodiment of the invention is especially designed and to which it is particularly applicable.

In order to develop the safety and danger conditions in themotors D, D each is provided with a-danger circuit 1 or 1: and a safety circuit 2 or 2, both of which, for convenience, are supplied from a single conductor 3 01'3, connected at a point 1 or t in the working .conductor 5 of the electric railway. TO interrupt the circuits 1 or 1, they are provided with spaced termlnals 6 or 6, while for a similar purpose, the safety circuits 2 or 2 are provided with terminals 7 or'7, and to close these circuits between these terminals,- there is provided a bridging contact 8 or 8, each of which, for conveniently rendering the circuit closers reciprocal in their action, is used in common for the terminals of both the danger circuit and the safety circuit, each contact 8 or 8, however, being biased or set to normally bridge the terminals 6 or 6, so that the danger circuit is normally unbroken at that point, and being. made to bridge the terminals 7 or 7 only by the act of leaving the terminals 6 or 6. To control these double-acting contacts 8 or 8, in the direction to close the safety circuits, relay magnets 9 or 9 are provided, and in order to make these effective only at the will of anoperator, they are included in what I term manually actuated circuits 10 or 10, which include switches to be operated at will, and which I call manual switches 11 or 11 located, in the illustrative embodiment, at the intersecting track or some other point of observation at which the operator will necessarily be apprised of the condition of the right-of-way.

In order to leave the safety appliance when it partakes of the form of a switch or other barrier, free to be moved to safety position by a car in passing out from the section, each danger circuit 1 or 1 is provided with an additional pair of terminals 12 or 12, normally open so as to interrupt the supply of current to the operating motor, and in order to close this additional break and insure the danger position as each car approaches the section, sai additional breaks are adapted to be closed by the armature 13 or 13 of a relay magnet 14 or 1 1 which is in the pilot circuit 15 or 15, under control of the car-operated switch 16 or 16. As soon as a car running toward the left in Fig. 1 passes beyond the actuating zone of the car operated switch 16, at the entering end, power is withdrawn from the danger circuits and the safety appliances are left neutral; that is to say, if in the form of a signal, it is free to assume any predetermined normal position, or if, as illustrated in the drawing, it has the form of a switch point presented in the direction to influence the car approaching the section, it remains in the position given it by the last energization of motor D, that is to say, as shown in Fig. 1, obstructing the passage of the car along the straight track. When the car, for instance, is approachin a section end from the right in Fig. 1 and c oses the car actuated switch 16, the safety appliance is at once effective acting to forbid passage, if in the form of a signal or to threaten derailment if in the form of a switch point C as illustrated, and remaining so set until the manual switch 11 is actuated. Similarly a car coming from the right and on the point of leaving the section will actuate switch 16 to hold the safety appliance closed as long as the switch 16 is influenced by the contact of the car trolley. But directly such influence is over, the circuit 15 is broken and power withdrawn from the danger circuit, thus again leaving the safety appliance neutral.

In the case of a switch point C, the latter will then remain open, as seen in Fig. 1. Obviously the wheel flanges of the next car coming in the same direction, that is leaving the section at switch 16, will push the switch point C outward only to be opened again the next moment by the switch 16. In this manner, each safety appliance will block the car upon entering the section only until presafety circuit is normally open by the resting of the double-acting relay armature upon the danger circuit terminals, the danger circuit is likewise normally open by reason of its second interruption, at which the armature of the pilot relay rests away from the terminals until a car approaches. Another advantage of thus having a second break with a pilot circuit, instead of having the appliance moved to danger position whenever it is released from the manually actuated circuit, is that while the car enforces the danger condition by approach ing the switch 16 and necessitates closing the manually actuated circuit 10, to restore the safety condition, the manually actuated circuit may be released as soon as the car has passed out of the range of switch 16 and before it reaches the track switch C, without restoring the track switch to danger. This condition results from the fact that as soon as switch 16 is released by the car passing out of range, armature 13 drops and" opens the danger circuit, and if the voluntary circuit 10 has been held closed until this takes place, the switch will thereafter remain in safety position.

In order to render the danger relay at both ends responsive to the trolley switch at either end, the pilot circuits 15 and 15 are connected by a conductor 15. It is to be understood that the several circuits are suitably grounded, the pilot circuits being grounded, for instance, at 15, 15; the danger and safety circuits grounded through the motors D and D, and the voluntary circuits grounded through the switches 11 and 11 Trolley switch 16 or 16 may partake of any approved form that will respond to the presence of the car, but I prefer a form such as shown in Fig. 3, because it responds to the approaching car gradually, by reason i of the lifting of the trolley wire 5 and through it the plunger 16 and switch blade 16, so as to close the circuit from the trolley wire through said switch blade and termi nal l7, whence the current passes to the pilot circuit 15 or 15. Another advantage of this form of switch is that it remains un der the influence of the car for a considerable distance on both sides of the switch. This switch forms the subject matter of my application, Serial No. 10,556 of even date herewith, and need not be further described here.

The motors D and D may be of any suitable type, such for instance as the double solenoid magnets 19, 18, in circuit, respectively, with the danger circuit and the safety circuit. controlling the plunger ar mature 20 which may be connected directly with the switch and madeto move it in opposite directions according to the winding that is for the time being energized.

Switches 11, 11* may be of any approved type. The one shown consists of a foot plunger 21 normally moved by a spring 22 in the direction of opening the circuit, but adapted to be depressed between the spring contacts 23, when it is desired to close the circuit.

I claim:

1. In a railway safety appliance, an electrically actuated safety device adapted to assume a safety position and a danger position; means adapted to set said device in the danger position, comprising a danger circuit connecting said safety appliance with a source of current, a relay controlling said danger circuit, a pilot circuit including the winding of said relay, and a car actuated switch in said pilot circuit adapted to be controlled by the presence of a car; and means for shifting said safety appliance to the safety position, comprising a safety circuit connecting said safety appliance with a source of current, a second relay controlling said safety circuit, a relay circuit including the winding of said second relay, and a 9 manual switch controlling said relay cir cuit, located at an observation point remote from the safety device the armature of said second relay normally resting upon the terminals in the danger circuit.

2. In a railway safety appliance, an electrically actuated safety device adapted to assume a safety position and a danger position; means adapted to set said device in the danger position, comprising a danger circuit connecting said safety appliance with a source of current, a relay controlling} said danger circuit, a pilot circuit including the winding of said relay, and a car actuated switch in said pilot circuit adapted to be controlled by the presence of a car; and means for manually shifting said safety appliance to the safety position, comprising a safety circuit connecting said safety appliance with a source of current, a second relay controlling said safety circuit. a relay circuit including the winding of said second relay, and a manual switch controlling said relay circuit, located at an observation point remote from the safety device; the armature of said second relay normally resting upon terminals in the danger circuit, and being adapted to open said danger circuit when the safety circuit is closed.

3. In a railway safety appliance, an elec- 0 trically actuated safety device adapted to assume a safety position and a danger position; means adapted to set said device in the danger position. comprising a danger circuit connecting said safety appliance with a source of current. a relay controlling said danger circuit. a pilot circuit including the winding of said relav. and a switch in said pilot circuit ada ted to be controlled by the presence ofa car, and means for shifting .of the other, and said safety appliance comprising a track-switch adapted to retain the position imparted by either of its controlling circuits, until positivelv moved therefrom by the other circuit the armature of said second relay being adapted to open .said danger circuit when the safety circuit is closed.

4. In a railway safety appliance, a safety device adapted to assume a safety position and a danger position, a double-acting motor for positively throwing said device to its respective positions, a danger circuit,. and asafety c1rcu1t, respectively, adapted to control said motor and energize it in the .directions to establish the respective positions of the safety device, a reciprocallyacting circuit closer controlling both the .danger circuit and the safety circuit normally assuming a position to close the danger c1rcu1t, a manually actuated c1rcu1t adapted to actuate said circuit closer to open the danger circuit and close the safety circuit, and'a remote switch in said manually actuated circuit.

5. In a railway safety appllance, a safety device adapted to assume a safety position and a danger position, a double-acting motor! for pos1t1vely throwlng said device to its respective positions, a danger circuit,

-and a safety circuit, respectively, adapted to control said motor and energize it in the directions to establish the respective posi- "tions of the safety device, a reciprocally- -45- danger circuit and the safety circuit normally assuming a position to close the danacting circuit closer controlling both the ger circuit, a second break in the'danger circuit, said second break being normally open, a pilot circuit including a relay con- 7 trolling said second break, a manually actuated circuit adapted to actuate said circuit closer to open the danger circuit and close the safety circuit, and a remote switch in said manually actuated circuit.

. 6. In a railway safety appliance, a safety device adapted to assume a safety position and a danger position, adouble-acting motor 7 I for positively throwlng sald device to its respective'positions, a danger circuit, and a safety circuit, respectively adapted to control said motor and energize it in the directions'to'establish the respective positions of V the safety device, a reciprocally-acting circuit closer controlling both the danger circuit and the safety circuit normally assuming a position to close the danger circuit, a second break in the danger circuit, said second break being normally open, a pilot cir cuit including a relay controlling said second break, a car-actuated switch controlling said pilot circuit, a manually actuated circuit adapted to actuate said circuit closer to open the danger circuit and close the safety circuit, and a remote switch in said manually actuated circuit.

7. In a railway safety appliance, a safety device adapted to assume a safety position and a danger position, a double acting motor for positively throwing said device to its respective positions, a danger circuit, and a safety circuit, respectively, adapted to control said motor and energize it in the directions to establish the respective posi tions of the safety device, a reciprocallyacting circuit closer controlling both the danger circuit and the safety circuit normally assuming a position to close the (langer circuit, a second break in the danger circuit, said second break being normally open, a pilot circuit including a relay controlling said second break, a car-actuated switch controlling said pilot circuit, a manually actuated circuit adapted to actuate said circuit closer to open the danger circuit and close the safety circuit, and a remote switch in said manually actuated circuit; said car-actuated switch being constructed to normally open the pilot circuit and to return to its normal position after the car leaves it and before it reaches the safety device.

8. In a safety appliance for protecting opposite ends of a railway section, safety devices located at the respective ends, and each adapted to assume a danger position and a safety position, a danger circuit and a safety circuit for each safety device, reciprocally-acting circuit closers for the respective ends, controlling the danger and safety circuits, manually actuated circuits having controlling switches located at points remote from the points at which cars are arrested by the safety devices, pilot circuits also controlling the danger circuits, and means through which the pilot circuits are controlled by the presence of a car; the pilot circuits at the respective ends being connected and being both responsive to the presence of a car at either end of the section.

9. In a railway safety appliance for protecting both ends of a track section, the combination of safety devices adapted to prevent the passage of a car at the respective ends of the section, double-acting motors adapted to set the safety devices in danger and safety positions, danger and safety circuits at the respective ends controlling said motor, double-acting relays at the respective ends, each adapted to rea trolley svvitch at each end, responsive to the presence of a car at that end, each trolley switch being adapted to close the pilot 15 circuit for both ends, independently of the trolley switch at the other end.

The foregoing specification signed at Lemoyne, Pennsylvania, this 12th day of February, 1915.

JAMES C. THOMPSON.

In presence of H. W. SNoDeRAss, G. M. GLENN.

flopieu of thinm patent may be obtained for five cents each, by addressing the "Commissioner of Eatento, Washington, D. 0." 

